End Caps for Structural Members

ABSTRACT

The invention provides a method of constructing a multi-storey building from modular panel components. Each panel component comprises a framework of cold-formed C-profile structural steel members including vertical members, horizontal members and optional diagonal cross-brace members. The vertical members include some load-bearing structural uprights of the finished building, each of which is provided with an end cap on each of its top and bottom ends, connected to the corresponding load-bearing structural upright by welding or by brazing. Each end cap comprises a back plate portion secured across the open side of the C-profile of the associated structural upright, to side plate portions secured to opposite sides of the associated structural upright and an end plate portion which lies across the otherwise open end of the associated structural upright. The end plate portion is in continuous metal-to-metal contact with the associated load-bearing structural upright, so that in the finished building the end caps at the top ends of the load-bearing structural uprights of one storey are in contact, either directly or via one or more metal shim plates, with the interior faces of a C-profile horizontal structural member spanning two or more structural uprights or with the end caps at the bottom ends of the load-bearing structural uprights to the next higher storey. This construction, relying as it does on continuous metal-to-metal contact, enables the building of higher structures than would otherwise be possible using cold-formed C-profile structural steel members.

FIELD OF THE INVENTION

The invention relates to a method of constructing a multi-storey building from modular panel components.

BACKGROUND ART

In modular building construction it is known to assemble a building from factory-formed modular building panels each fabricated from cold-formed structural steel. The steel is cold-formed into various profiles to create the necessary rigidity. One well documented profile is a so-called C-profile in which the sheet steel is folded longitudinally to create a front face, two side faces each in a plane perpendicular to the front face, and two inturned flange portions down the longitudinal edges of the side faces remote from the front face. Cold-formed C-section structural steel members can be assembled, generally by bolting together, into frameworks which include some vertical members, some horizontal members and optionally one or more diagonal cross-brace members. Z-section cold-formed structural steel members are secured to the frameworks to provide offset support shoulders creating an edge rebate into which solid shim panels can be secured.

One disadvantage of such a method of construction is that it is very limited in its ability to support multiple storeys. As a generality, buildings made by the known framework panel construction method can be three or at most four storeys high. For higher buildings it is necessary to incorporate more rigid load-bearing vertical pillars which may be of masonry, reinforced concrete or hot-rolled steel section such as I-section girders.

This invention is based on the realisation, supported by structural analysis calculations, that the known framework panel system as discussed above can be used in the construction of buildings six, eight, ten or even twelve storeys high after only minor modification to strengthen the C-section structural members at the areas of maximum potential weakness and to create a reliable and uniform transmission of the vertical load of the building through mutually aligned C-section structural uprights.

THE INVENTION

The invention provides the method of construction identified in claim 1 herein. When the structural uprights have their end caps in direct contact with one another or separated only by shim plates, the transmission of the vertical load of the building directly from one structural upright to the next through abutting end caps and through any associated shim plates enables the vertical load to be spread evenly throughout the entire building in a manner and to an extent never before achieved. When the structural uprights and their end caps slot into the internal recess of U-shaped horizontal members spanning two or more of the structural uprights, the vertical load is shared between adjacent C-section structural uprights and is thereby shared even more evenly throughout the building.

The entire building shell is constructed from modular framework body panels before any solid wall panel partitioning or cladding is added. Preferably the end cap at one end of each structural upright, for example the top end, is provided with one or more spigots which are received in one or more locating apertures in the end cap at the adjacent end, for example the bottom end, of the aligned structural upright of the framework body panel of the adjacent storey, for example the storey above. This ensures rapid longitudinal alignment of the structural uprights of successive storeys. The spigots are preferably held in place by swaging in apertures punched into the end plate portions of the end caps during their initial manufacture. Preferably the spigots are commercial fasteners sold under the Trade Mark AVDALE, which are intended to create a recessed screw threaded anchor point in a metal plate. The method of construction described above envisages those fasteners being inserted from the underside of the end plate portion of each end cap, so that they project from the end plate portion as a smooth-sided cylindrical steel spigot rather than depending from the top face of the end plate portion to create an internally screw-threaded recess.

DRAWINGS

FIG. 1 is a perspective view of a framework panel component of a modular building constructed according to the invention;

FIG. 2 is a perspective view of a top end of one of the cold-rolled C-section structural uprights without its end cap;

FIG. 3 is a perspective view of the end cap to be secured to the end of the structural upright of FIG. 2;

FIG. 4 is a perspective view of the end cap of FIG. 3 viewed from the direction of the arrow A in FIG. 3;

FIG. 4A is a side elevation, taken in the direction of the arrow 4A of FIG. 4, of the end cap of FIG. 4, but showing the joint between the side and end plate portions of the end cap in greater detail. FIG. 4A also shows, in phantom, the associated structural upright and a U-shaped horizontal member which in use would span two or more such structural uprights;

FIG. 4B is an enlarged detail of one corner of the end cap of FIG. 4A, but shown in perspective view;

FIG. 4C is a perspective view similar to that of FIG. 3, but of a modification of the end cap of FIG. 3;

FIG. 5 is a plan view of a flat piece of steel before it is bent and welded or brazed into the end cap of FIGS. 3 and 4;

FIG. 6 is a plan view of the structural upright of FIG. 2 with the end cap secured thereto, with the bottom end portion of an associated structural upright of the next storey of the building being shown in phantom lines;

FIG. 7 is a section through an AVDALE™ fastener fitted as a spigot to the end plate portion of an end cap; and

FIG. 8 is a perspective view of a part of the framework of panel components of a building during construction, before the addition of the solid wall panels to form the internal partitioning of the building and cladding to form the outer walls of the building.

The invention relates to a method of constructing a multi-storey building from modular panel components. FIG. 1 is a perspective view of one such modular panel component. It is of standard room height and its length is preferably a standard length so that multiples of the identical building panel can be made up into a variety of building shapes and sizes, or possibly mixing together two similar building panels of the same height but of different standardized lengths can provide more flexibility to the designer. If a building length or width is desired that cannot be made up from standardized length panels, then preferably a whole number of uniform standardized length panels is used, with a single custom-made building panel constructed generally as illustrated in FIG. 1 being used to bring the array to the precise length specified by the architect.

The modular panel of FIG. 1 comprises a framework of cold-formed C-profile structural steel members. These include vertical members 1 to 5, horizontal 6 and 7, and diagonal cross-brace members 8 and 9. The framework is assembled in a factory using an assembly jig which ensures that each panel can be made to precisely the same dimensions, working to extremely low tolerances. The joints are all welded or brazed.

The vertical members 1 and 5 form load-bearing structural uprights of the finished building, and each is provided at its top and bottom ends with end caps 10. The precise construction of which is explained with reference to FIGS. 2 to 5. The end caps end at the top and bottom of the respective load-bearing structural uprights 1 and 5 are identical except for the addition of locating spigots 11 in the end caps 10 along the top of the panel, cooperating with corresponding apertures in the end caps along the bottom of the panel.

Each loading-bearing structural upright 1 and 5 extends the full height of the panel component, emanating in a flat end (top or bottom) as illustrated in FIG. 2. A chamfer 12 is formed across the top and bottom ends of each inturned side flange portion 13 of the C-profile of vertical member 1 or 5, as shown in FIG. 2. The purpose of this chamfer 12 is explained later.

Each end cap 10 is formed by bending a metal blank that has been cut to the shape shown in FIG. 5. In FIG. 5, the fold lines are shown in phantom. The blank is formed from sheet steel and comprises a back plate portion 10 a, a pair of wing portions 10 b and an upstanding portion 10 c. The wing portions 10 b are bent over by 90° from the back plate portion 10 a to create side plate portions of the end cap as shown in FIGS. 3 and 4, and the upstanding portion is bent over by 90° to create an end plate portion, also as shown in FIGS. 3 and 4. The bending is a cold press bending operation, and after the bending is complete the edges of the side plate portions 10 b are secured to edges of the end plate portion 10 c by welding or by brazing as indicated at 14 in FIGS. 3 and 4.

The formed end cap 10 is dimensioned to fit accurately and securely over the respective upper or lower end of the structural upright 1 or 5. Because any end formed by cold-bending a steel sheet is necessarily a small arc as opposed to a true right angle, the internal bend line between the back plate portion 10 a and the end plate portion 10 c is arcuate, and chamfer 12 is established on the structural uprights 1 and 5 to ensure that when fitted the end plate portion 10 c lies completely flat in metal-to-metal contact with the whole of the top or bottom of the structural upright 1 or 5.

The end caps 10 are secured to their associated structural uprights 1 and 5 by welding or brazing. Preferably the back plate portion of the end cap is welded or brazed to each of the mutually aligned edge portions of the open end of the associated C-section structural upright 1 or 5. The side plate portions of each end cap may be secured to the associated opposite sides of the structural upright 1 or 5 by screws or by welding or brazing. In either case the weld or braze may be a spot weld or a plug weld or braze. Thus the back plate portion 10 a spans the gap between the inturned slide flanges 13 of the structural uprights, so that when welded together the top and bottom of each structural upright is formed as a complete channel member with metal on all four side faces, as opposed to the remainder of the structural upright 1 or 5 which is open C-section.

The end caps 10 which sit on the top of the panel framework are fitted with a pair of protruding spigots 7 which protrude from apertures 15 cut from the end cap blank as shown in FIG. 5. The corresponding end caps of the bottom of the panel structure have no such spigots 11 fitted, but are formed with corresponding apertures 15. Each spigot is preferably a swaged anchor member such as those commercially available under the Trade Mark AVDALE. One such spigot is shown in section in FIG. 7. It comprises a retaining flange portion 11 a, an internally screw threaded portion 11 b and an intermediate portion 11 c which is of a thinner wall thickness than that of 11 b so that when the screw threaded portion 11 b is pulled downwardly using an appropriate setting tool, the intermediate portion 11 c swages over to lock the fastener to the aperture 15 in the end plate portion 10 c. The outer surface of the screw threaded portion 11 b is cylindrical, so that the secured fastener act as a spigot extending perpendicularly out from the end plate portion 10 c. If all of the apertures 15 in the end cap blanks are accurately positioned, as they can be if for example they are cut by laser, then the spigots 11 protruding from the top of the framework are accurately aligned with the corresponding apertures 15 in the end caps 10 of the bottom, so that successive storeys of a building made by the method of the invention can be very accurately positioned one over the other.

FIGS. 4A and 4B show in greater detail the preferred construction of the end plate and side plate portions of the end cap and their precise inter-engagement. Outer side edges 10 c′ of the end plate portions 10 c abut but do not overlie top side edges 10 b′ of the side plate portions 10 b, so that there remains a recess or chamfer to accommodate an internal form radius of an associated U-profile horizontal member 40 into which the end cap can be located. This makes it possible for the end cap to establish face-to-face contact with all three of the internal walls of the associated U-profile horizontal member 40 as illustrated in FIG. 4A in which the U-profile member 40 is shown in phantom line together with the associated structural upright which is shown with the reference number 42.

It will be noted that FIG. 4A shows no spigots 11. Where the end cap is to be fitted into a U-profile horizontal member spanning two or more structural uprights, it is possible that the spigots 11 may be omitted. Alternatively they may be included as already described, in which case they interfit with holes drilled through the horizontal web of the U-profile horizontal member 40.

An alternative end cap to that of FIGS. 3, 4A and 4B is shown in FIG. 4C. As with the end cap of FIGS. 3, 4A and 4B, it is made with a back plate portion 10 a, two side plate portions 10 b and an end plate portion 10 c formed by bending from a single cut metal blank similar to that of FIG. 5. However with the end cap of FIG. 4C there are shown holes 43 in the back plate portion 10 a, being the holes through which the plug braze or plug weld joins are made to connect the end cap to the aligned sides of the open face of the C-profile structural upright (not shown) to which it is joined. The holes 43 may be arranged in any suitable pattern. A slot 45 is made down each of the side plate portions 10 b. The two slots are identical, although only one is visible in FIG. 4C. In use the end cap at the end of a structural vertical upright is pushed into an inverted U-profile channel section wall plate, and if that channel section has been formed with internally directed dimples in its parallel side faces, those dimples can slide down the slot 45 to locate the end cap longitudinally of the U-profile wall plate. By forming that wall plate accurately to size and locating the dimples accurately in the factory using numerically controlled machinery, the location of the end cap along the wall plate can be both positive and accurate even when the building is being erected under site conditions. The slot 45 and the dimples in the U-profile wall plate provide an inexpensive alternative to the use of the AVDALE™ spigot location means discussed earlier.

The end caps 10 are preferably secured to the corresponding structural uprights 1 and 5 by plug welding or by plug brazing, using holes (not shown) which are pre-formed in the blanks for the end caps 10. In addition, bolt holes 16 are formed, to enable the assembled wall panels to be pulled together and secured fast one to the other during construction.

When erecting a multi-storey building by the method of the invention, a first storey is first erected, by bolting and/or welding an appropriate number of panel frameworks one to the other. To build the next higher storey, similar building panels are used, with the structural uprights (1 and 5) both the higher of the two storeys being placed directly over the corresponding structural uprights of the storey just completed. Metal shims (one of which is shown as 17 in FIG. 6) are placed over the tops of the end caps 10 of the structural uprights of the floor just completed, and the number and thickness of the shims 17 is adjusted until the new storey being built is exactly horizontal. The spigots 11 pass through holes cut in the shims. They continue on to engage in the apertures 15 cut in the end caps at the bottom of the structural uprights of the next higher storey, and the metal-to-metal contact between the top edge of the structural uprights and the peripheral internal edge of the end plate portion of each end cap means that there is a continuous longitudinal run of metal through all such structural uprights running from the lowest to the highest storey of the building. That enables a significantly higher building to be constructed than if the building load were transmitted generally along the whole of the top and bottom faces of the horizontal members 6 and 7.

FIG. 8 illustrates just how versatile the method of construction of the invention can be. The end caps can be used whenever the structural uprights meet horizontal members of the framework in an L-configuration as shown at 20, a T-configuration as shown at 21, a 3-way mutually perpendicular junction as shown at 22, a 4-way mutually perpendicular junction (not illustrated) or a 5-way mutually perpendicular junction as illustrated at 23. All of those junctions more advanced than the simple L-shaped junction 20 can be created by bolting together two, three or four panel components, each of which is constructed as previously described.

Once the building framework has been constructed from the modular panel components as described above, floors ceilings and wall cladding can be added. Preferably individual panel components contain the necessary anchorages for the doors and windows, so the final finishing of the building can be carried out rapidly according to conventional methods. 

1: A method of constructing a multi-storey building from modular panel components wherein: each panel component comprises a framework of cold-formed C-profile or U-profile structural steel members including vertical members and horizontal members of which at least some of the vertical members are C-profile members forming load-bearing structural uprights of the finished building; each of the said load-bearing structural uprights is provided at each of its top and bottom ends with an end cap which is connected to the load-bearing structural upright by welding or by brazing, and which comprises a back plate portion secured across the open side of the C-profile of the associated structural upright, two side plate portions secured to opposite sides of the associated structural upright, and an end plate portion which lies across the otherwise open end of the associated structural upright, the end plate portion being in continuous metal-to-metal contact with the associated end of the load-bearing structural upright; and in the finished building the end cap at the top of each of the load-bearing structural uprights of one storey is in contact, either directly or via one or more metal shim plates, with the internal walls of a U-profile horizontal member spanning two or more of the structural uprights or with an end cap at the bottom end of one of the load-bearing structural uprights of the next higher storey so as to transmit the vertical load of the building directly through the end caps down through the associated load-bearing structural uprights. 2: A method according to claim 1, wherein the end caps are formed by cold-bending a steel sheet so that two wing portions are bent over by 90° from the back plate portion to create the side plate portions and an upstanding portion is bent over by 90° from the back plate portion to create the end plate portion, and edges of the side plate portions are secured to edges of the end plate portion by welding or by brazing. 3: A method according to claim 2, wherein the end caps are made to establish face-to-face contact with all three internal walls of an associated U-profile horizontal member spanning two or more of the structural uprights, by forming the outer side edges of the end plate portion of the end cap to abut but not completely to overlie the associated edges of the side plate portion thereof and by connecting together the abutting edges by a seam weld or braze so as to define therebetween a recess or chamfer to accommodate an internal form radius of the associated U-profile member. 4: A method according to claim 1, wherein one of the pair of end caps secured to each of the load-bearing structural uprights is provided with one or more spigots projecting longitudinally from the end cap and the other of the pair of end caps secured to the same structural upright is provided with one or more apertures in its end plate portion, so that in the finished building each of the spigots projecting from the structural uprights of one storey is located in a corresponding one of the apertures to locate the structural uprights of adjacent storeys in longitudinal alignment one with another. 5: A method according to claim 4, wherein the spigots are secured to their associated end caps by passing each one through an aperture in the end plate portion of the end cap and securing it in position by swaging. 6: A method according to claim 5, wherein the spigots are internally threaded. 7: A method according to claim 1, wherein the back plate portion of the end cap is welded or brazed to each of the mutually aligned edge portions of the open end of the associated C-profile structural upright so as to create, at the said top or bottom end of the C-section structural upright a complete box section profile. 8: A method according to claim 7, wherein each weld or braze between the back plate portion of the end cap and the mutually aligned edge portions of the open end of the associated C-profile structural uprights is a spot weld or a plug weld or plug braze.
 9. A method according to claim 7, wherein the side plate portions of each end cap are secured to the opposite sides of the associated C-profile structural uprights by screws or by welding or brazing. 10: A method according to claim 1, wherein the framework of each panel includes at least one diagonal cross-brace member which is also a cold-formed C-profile structural steel member. 